Bug 880917 - Remove XPConnect version munging test. r=luke

This test calls the version() shell command, and expects it to work like an
override, rather than the dumb compartment-mutator that I'm turning it into.
Let's just kill the test.

js/xpconnect/tests/unit/bug596580_versioned.js

@@ -1,3 +0,0 @@
-/* Some constructs that require a high default version number. */
-let x = 12;
-function simpleGen() { yield 12; }

js/xpconnect/tests/unit/test_bug596580.js

@@ -1,19 +0,0 @@
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-
-function run_test() {
-  var file = do_get_file("bug596580_versioned.js");
-  var ios = Cc["@mozilla.org/network/io-service;1"]
-              .getService(Ci.nsIIOService);
-  var uri = ios.newFileURI(file);
-  var scriptLoader = Cc["@mozilla.org/moz/jssubscript-loader;1"]
-                       .getService(Ci.mozIJSSubScriptLoader);
-  scriptLoader.loadSubScript(uri.spec);
-  version(150)
-  try {
-      scriptLoader.loadSubScript(uri.spec);
-      throw new Error("Subscript should fail to load.");
-  } catch (e if e instanceof SyntaxError) {
-      // Okay.
-  }
-}

js/xpconnect/tests/unit/xpcshell.ini

@@ -5,7 +5,6 @@ tail =
 [test_bogus_files.js]
 [test_bug408412.js]
 [test_bug451678.js]
-[test_bug596580.js]
 [test_bug604362.js]
 [test_bug641378.js]
 [test_bug677864.js]